Aspects of the present invention relate generally to the field of integrated circuit design, and more specifically to the creation of guard rings.
Integrated circuit (IC) design is increasingly complex, sometimes involving millions of elements, shapes or geometries, and may be facilitated with an electronic design automation (EDA) tool that allows a designer to interactively position (“place”) and connect (“route”) various shapes on the circuit. As part of the process of physical design, the EDA tool creates a circuit layout containing the physical locations and dimensions of the circuit's components, interconnections, and various layers from the original design that may then be fabricated, creating the IC. The designed IC is eventually fabricated by transferring or printing the circuit layout to a semiconductor substrate in a series of layers that collectively will form the features that constitute the devices that make up the components of the integrated circuit.
During the process of physical design of the IC, guard rings are often added to enclose one or more devices (e.g. transistors) in the layout. The added guard rings isolate and protect the enclosed device(s), for example, against a latchup problem, or from external noise. Often, there are very strict and/or complex rules for the correct creation of guard rings, and manual or custom creation is difficult as a result. Additionally, as the geometries of a circuit design get increasingly smaller, it would be advantageous to create guard rings that are similar to or reflect the devices being enclosed, or at least are designed in consideration of those devices. However, due to the strictness and/or complexity of the rules involved in creating a guard ring, adjusting conventional approaches to reflect the associated devices would be complex, time and resource exhaustive, and error prone.
Accordingly, there is a need in the art for a system, with very simple inputs, that can construct the guard ring structure correctly.